@article{ref1,
title="Differences in excitatory and inhibitory neurotransmitter levels between depressed patients and healthy controls: a systematic review and meta-analysis",
journal="Journal of psychiatric research",
year="2018",
author="Godfrey, Kate E. M. and Gardner, Abby C. and Kwon, Sarah and Chea, William and Muthukumaraswamy, Suresh D.",
volume="105",
number="",
pages="33-44",
abstract="Dysfunction of gamma-aminobutyric acid (GABA) and/or glutamate neurotransmitter systems have increasingly been implicated in the aetiology of Major Depressive Disorder (MDD). It has been proposed that alterations in GABA and/or glutamate result in an imbalance of inhibition and excitation. In a review of the current literature, we identified studies using Magnetic Resonance Spectroscopy (MRS) to examine the neurotransmitters GABA, glutamate, and the composite glutamate/glutamine measure Glx in patients diagnosed with MDD and healthy controls. <br><br>RESULTS showed patients with MDD had significantly lower GABA levels compared to controls (-0.35 [-0.61,-0.10], p = 0.007). No significant difference was found between levels of glutamate. Sub-analyses were performed, including only studies where the Anterior Cingulate Cortex (ACC) was the region of interest. GABA and Glx levels were lower in the ACC of MDD patients (-0.56 [-0.93,-0.18] p = 0.004, and 0.40 [-0.81,0.01] p = 0.05). This review indicates widespread cortical reduction of GABA in MDD, with a trend towards a localised reduction of Glx in the ACC. However, given both GABA and glutamate appear decreased a simple interpretation in terms of an imbalance of overall excitation-inhibition is not feasible.<br><br>Copyright © 2018. Published by Elsevier Ltd.<p /> <p>Language: en</p>",
language="en",
issn="0022-3956",
doi="10.1016/j.jpsychires.2018.08.015",
url="http://dx.doi.org/10.1016/j.jpsychires.2018.08.015"
}